Fluid distributing-collecting system and its process

ABSTRACT

A fluid distributing-collecting system for a device for bringing fluids and solids into contact comprising several distributor plates and several panels for mixing, distributing or extracting fluids. The system comprises at least one level 1 chamber in connection with the outside of said device with at least one hose and, at least one level 2 chamber that is linked with the level 1 chamber and that comprises one or more connecting hoses of a selected length that are arranged in at least one zone. The zone is identified relative to an angle α relative to a radius of a plate and corresponds to a given angle sector, whereby said hose lengths, angle α and the angle sector are selected so that the injected fluid arrives approximately at the same time on all of the panels of the same plate. This system is used for separation of paraxylene in a simulated moving bed.

CROSS REFERENCE TO RELATED APPLICATION

This application is related to applicants concurrently filed applicationU.S. Ser. No. 09/389,073, entitled "Distributor-Mixer-Extractor OfFluids And Associated Process, based on French Application 98/10.996filed Sep. 2, 1998.

This invention relates to a fluid distributor-collector or a fluiddistributing-collecting system that is used, for example, in a devicefor bringing fluids and solids into contact.

The invention can be applied in particular in the area of chromatographyfor fluids in a gaseous state, liquid state or supercritical state.

The invention relates to a distributing-collecting system that can beused in a separation process in a simulated moving bed of paraxylenethat is contained in a mixture of xylenes and ethylbenzene, for thepurpose of terephthalic acid synthesis, an intermediate petrochemicalproduct in the production of textiles.

The invention can also be used in processes for separating, for example,a xylene and ethylbenzene isomer mixture, a mixture of a compound thatis selected from saturated fatty acids and their esters, a mixture ofparaffin and olefins, a mixture of isoparaffins and normal paraffins,and other compounds.

The device according to the invention can operate in a liquid phase, avapor phase or in a supercritical phase and in all of the separationareas of chemistry, petrochemistry or petroleum, for example.

In the area of separation processes, it is customary to rely onsimulated moving bed systems to separate the elements that comprise, forexample, at least two different chemical compounds or else two isomersof the same compound. The adsorption material that is used is, forexample, a solid.

The technological background that illustrates the implementation of anadsorption device with simulated countercurrent is described in, forexample, U.S. Pat. No. 2,985,589.

In these processes, a main fluid that is introduced via a pump flowsthrough the solid bed along the central axis of the column. To obtainthe best performances of this process, it is important that the mainfluid flows through the adsorbent according to a piston-type flow (plugflow) to have a composition and a flow front that are the most uniformpossible at all points of the surface of the adsorbent bed.

For this purpose, the prior art describes various means that attempt toobtain and to maintain such a flow.

The device that is described in U.S. Pat. No. 3,523,762 that is arrangedbetween two adsorbent beds makes it possible to remix the fluid whileflowing.

For applications with simulated countercurrent, the device that isdescribed in U.S. Pat. No. 3,214,247 shows a structure that comprises anupper grid, a lower grid for holding particles and two non-perforatedhorizontal baffles that are positioned between these two grids. Thefluids are added or extracted from a central space between thedeflectors via a hose that traverses the entire section of the device.Such a device makes it possible to remix the fluid while flowing in thecolumn and also to ensure a good mixing of a fluid that is added to themain fluid.

It is also possible to mention the two patents U.S. Pat. No. 5,792,346and U.S. Pat. No. 5,755,960 that describe fluid distribution panels orDME whose function in particular is to mix, extract or add fluids. TheseDME are connected to fluid distributing-collecting circuits that seek tohomogenize the passage time of the particles of the fluid from outsideof the column to the panels and conversely from a panel to an outsidecollecting network.

Actually, the dispersion into the composition of the flow and in thepassage time of the fluid particles can also be obtained in the way inwhich the fluids are distributed or extracted up to the DME or from theDME.

Some distributing or collecting circuits are designed for reducing thedispersion time of the fluids. The geometry of these circuits isgenerally adapted to the geometry of the plates and to the arrangementof the DME at these plates.

For example, in U.S. Pat. No. 5,792,346, the circuit for distributing orextracting secondary fluids shows a distribution symmetry and anisolength of the transfer lines of the fluids. These circuits allow adistribution of the separator-type fluids or a radial distribution fromor to the center of the separation column.

In U.S. Pat. No. 5,755,960, the distributing-collecting circuit consistsof several radial hoses that comprise several branches for distributingor collecting secondary fluids to or from each panel that forms adistribution plate. The branches are distributed over the whole or overa portion of the length of the radial-feed hose to which they areconnected. Another variant consists in distributing the fluids from aring or half-rings that are positioned on the periphery of the column.The fluid transfer hoses up to a DME are distributed over the entirelength of the ring or half-rings.

Patent EP-074,815 describes a system for distributing fluids inside adevice for bringing fluids and solids into contact that comprisesseveral fluid distributing rings. The rings are mounted on a centraltube of the device and arranged between adjacent levels of fluiddistributor plates. Several distribution pipes that extend between afluid distributor plate and the distribution ring make possible theinjection and/or collection of fluid.

All of these systems meet the need of obtaining a piston-type flow or"plug flow" inside of a device for bringing it into contact to minimizethe passage times of fluids so that they arrive virtually at the sametime in the different panels of the same plate.

The object of this invention relates to a fluid distributing-collectingsystem that in particular makes it possible to obtain and to maintain aplug flow, a homogeneity of the composition of this flow, and tominimize the dispersion time of the fluids that are injected orextracted in the panels that form a distribution plate.

Throughout the rest of the description, a level 1 chamber is defined asa chamber whose function is to divide a fluid at least in two or tocollect two fluid flows, and a level 2 chamber is defined as a chamberthat ensures the division at least in two of a fluid that is obtainedfrom a level 1 chamber or the collection of at least two fluid flows tosend them to a level 1 chamber.

The term DME refers to a panel whose function in particular is tocollect, mix, extract or remix one or more fluids.

This invention relates to a fluid distributing-collecting system for adevice for bringing fluids and solids into contact, whereby said devicecomprises a chamber, at least one hose for introducing a main fluid andat least one hose for evacuating the main fluid, several distributorplates (Pn), whereby each of said plates comprises several panels formixing, distributing or extracting fluids or DME.

It is characterized in that it comprises:

at least one hose that makes it possible to link said device and theoutside,

at least one chamber (N₁) that is linked with said hose or hoses,

one or more connecting hoses C(N₂₀)j, C(N₂₁)j, that link the chamber andat least one of the DME of a plate (Pn), whereby connecting points rj ofsaid hoses are located in a zone (Z₂₀, Z₂₁), whereby the positioning ofsaid zone is determined by an angle α counting from one of the radialaxes of said plate (Pn), whereby each of the connecting hoses has alength li, whereby the value of each of lengths li, of angle α and oflength Zr of the zone are selected so that the passage time of thefluids between a panel (DME) and hose or hoses (1, 2) is essentiallyidentical for all of the fluids.

The chamber ensures, for example, the division of the fluid into atleast two flows.

According to an embodiment, the distributing-collecting systemcomprises, for example:

at least one level 1 chamber (N₁) that ensures a twoway division orcollection of the fluid flow, whereby chamber (N₁) is linked with thehose or hoses,

at least one so-called level 2 chamber (N₂₀, N₂₁), whereby the chambersensure a two-way division or collection of the fluid flow that comesfrom or is sent to chamber or chambers (N₁),

one or more connecting hoses (C(N₂₀)_(j), C(N₂₁)j that extend between atleast one level 2 chamber (N₂₀, N₂₁) and at least one of the DME of aplate (Pn), whereby connecting points rj of the hoses are located in azone (Z₂₀, Z₂₁), whereby the positioning of the zone is determined by anangle α counting from one of the radial axes of plate (Pn), whereby eachof the connecting hoses has a length li, and whereby the value of eachof lengths li, angle α and length Zr of the zone are selected so thatthe passage time of the fluids between a panel (DME) and the hose, orhoses, is essentially identical for all of the fluids.

Angle α is, for example, between 30 and 90 degrees, preferably between50 and 60 degrees, and length Zr for a zone that corresponds to anglesector α+/-ε is between 3 and 30 degrees and preferably between 7 and 15degrees.

This invention also relates to a device for bringing fluids and solidsinto contact that comprises a chamber that comprises an outside wall, atleast one hose for introducing and at least one hose for extracting amain fluid, several hoses for introducing or extracting secondaryfluids, several spaced levels of plates (Pn), whereby each plate (Pn)comprises one or more distributing-mixing-extracting panels (DME) ofsecondary fluids and a main fluid, at least one fluiddistributing-collecting system, characterized in that:

said distributing-collecting system is arranged on the periphery of thechamber,

said distributing-collecting system is connected with

at least one distribution plate (Pn),

said system comprises:

at least one hose that makes it possible to link the device and theoutside,

one or more level 1 chambers (N₁) that ensure a two-way division orcollection of the fluid flow,

one or more level 2 chambers (N₂₀, N₂₁), whereby the level 2 chambersensure a two-way division or collection of the fluid flow that comesfrom or is sent to level 1 chamber (N₁),

connecting hoses (C(N₂₀)_(j), C(N₂₁)j) that extend between a level 2chamber (N₂₀, N₂₁) and at least one of the panels (DME) of a plate (Pn),whereby the connecting points of the connecting hoses are located in azone (Z₂₀, Z₂₁), whereby the positioning of this zone is determined byan angle α counting from one of the radial axes of a plate (Pn), wherebyeach of the fluid connecting hoses has a length li, and the value ofeach of lengths li, angle α and length Zr of the zone are selected sothat the passage time of the fluids between a panel (DME) of a plate(Pn) and the hose for introducing or extracting fluids is essentiallyidentical for all of the fluids.

Angle α can be between 30 and 90 degrees, preferably between 50 and 60degrees, and length Zr that corresponds to the angle sector is between 3and 30 degrees and preferably between 7 and 15 degrees.

According to a variant embodiment, the device comprises at least oneplate that comprises at least one DME that has the followingcharacteristics:

at least one means for collecting a main fluid,

at least two injection and/or draw-off rails that allow the passage ofsecondary fluids that are each provided with openings, whereby the railsare arranged one on top of the other,

at least two mixing chambers that are provided with openings, wherebythe chambers are arranged on both sides of at least one of the rails andrelative to the openings,

means for distributing the fluid that is obtained from the mixingchamber,

means for separating said collecting and distributing means.

Each plate (Pn) can be divided into several panels or DME according to acutaway in parallels.

A plate can be divided into four sectors.

The upper rail has, for example, a function of collecting fluids, andthe lower rail has a function of injecting fluids.

The upper rail may have a function of injecting fluids, and the lowerrail may have a function of collecting fluids.

According to another variant embodiment, the upper and lower rails havea fluid injecting-collecting function.

The openings of the injection rail or rails are arranged such that thefluid jet that passes through strikes at least one portion of a solidwall of one of the mechanical elements of the DME.

The openings can be arranged alternately or at random.

The openings of the injection and/or draw-off rails are defined with,for example, the following parameters:

a diameter of between 2 and 15 mm and preferably in the range of 4 to 7mm,

a perforation span of between 25 and 400 mm and preferably between 50and 200 mm,

a rate of flow of the fluids of between 3-20 m/s and preferably between5-15 m/s; the value of the span that is under consideration with thevalue of the rate makes it possible to obtain a good mixing of thesecondary fluid and the main fluid.

The openings of the mixing chambers have, for example, the followingcharacteristics:

a diameter of between 10 and 25 mm, and preferably between 5 and 50 mm,

a perforation span that is selected from the interval 50-200 mm andpreferably in the interval of 25-400 mm,

a rate of flow of the mixture of between 1.0 and 2.0 m/s and preferablybetween 0.5-3.5 m/s.

This invention also relates to a process for separating at least onecompound from a mixture or an element by adsorption.

It is characterized in that a main fluid, from which it is sought toseparate some compounds, is brought into contact with an adsorbent thatis selected as a function of its ability to separate the compounds, andthe secondary fluids are injected and/or extracted via one or moredistributing-collecting systems.

It is possible to group the fluids by function (injection/or draw-off)or by nature or by flow rate value.

The system, device and the process according to the invention pertain tothe separation of a feedstock by chromatography for fluids in a gaseousstate, liquid state or supercritical state.

They can also pertain to the separation of paraxylene in a simulatedmoving bed.

The device according to the invention has in particular the followingadvantages:

because of the good distribution symmetry of the secondary fluids andthe main fluid, the mixture that is produced is improved over the entireplate, which imparts a more homogenous composition and a general plugflow to the circulating flow in the separation device,

to optimize the mixing of fluids inside the distribution panels, mixing,extraction, to remix the main fluid while flowing,

to reduce the time dispersion of the injection of fluids or theextraction of fluids to or from various panels that constitute adistribution plate.

BRIEF DESCRIPTION OF THE DRAWINGS

Other characteristics and advantages of the device according to theinvention will emerge from reading the description of examples that aregiven below as an illustrative and nonlimiting example by referring tothe accompanying drawings, where:

FIG. 1 represents a view in perspective of a fluiddistributing-collecting system example according to the invention thatis associated with a distribution plate,

FIGS. 2A and 2B show a diagram of a section of a plate and associateddistributing-collecting system,

FIG. 3 shows a cutaway view of a separation column that is provided witha distributing-collecting system of FIG. 1,

FIG. 4 shows a diagram of a section of a special example of adistribution panel,

FIGS. 5A and 5B show a top view and a section of an example ofarrangement of hoses for feeding a panel,

FIGS. 6A, 6B and 6C show different variant embodiments of a fluiddistributing-collecting system.

DESCRIPTION OF THE PREFERRED EMBODIMENT

FIGS. 1 and 2A, 2B show a fluid distributing-collecting system examplethat is associated with a fluid distribution plate that comprisesseveral panels or DME whose function is to mix, distribute or extractfluids.

The geometry and the hydraulic characteristics of this network areselected to obtain a distribution of secondary fluids that is the mostsymmetrical possible for the set of panels or injection-collection railsof a plate.

FIG. 1 showed two distributing-collecting systems that can be superposedand that are associated wtih a plate Pn. The number ofdistributing-collecting systems that are associated with a plate Pn is afunction in particular of the geometric dimensions of the DME with whichthey are connected.

The plate is referenced Pn, whereby n is the index of the plate when itis arranged, for example, in an approximately cylindrical separationcolumn such as the one that is described in FIG. 3. It has the shape ofa disk, for example, and is cut into several DME according to a cutawayin parallels (of meridian type), whereby the widths of the differentpanels can be equal.

The distributing-collecting system comprises, for example:

a so-called annular level 1 chamber N₁. Chamber N₁ communicates with theoutside of the column with a hose 1, 2, for example. These hoses allowthe introduction and/or the extraction of fluids. They can have specificfunctions, for example in the case where the different fluids aregrouped according to different variants of which some are describedbelow.

Annular rectangular-section chamber N₁, for example, extends on theinternal periphery of the adsorbent bed and ensures in particular atwo-way division or collection of the circulating flow of the fluids,

a so-called annular level 2 chamber N₂ with a rectangular section on theperiphery of the adsorbent.

In particular according to its function (injection, extraction orinjection/draw-off), it ensures respectively a division or a collectionor else a two-way division and/or collection of the fluid flow. Itsposition according to the function of the distributing-collectingsystem, due to the geometric space requirement, for example, can bearranged above (referenced N₂,) or below (referenced N₂₀) chamber N₁.

Junction J of a level 2 chamber N₂₀, N₂₁ with level 1 chamber N₁ isproduced, for example, with half of the periphery of its length.

An annular level 2 chamber comprises, for example, at each of its ends,one or more hoses C(N₂₀)j or C(N₂₁)j for connection with the panels of aplate; index j corresponds to the index of a panel that is linked withthe hoses. A hose C(N₂₀)j or C(N₂₁)j is connected to a zone (Z₂₀₁ Z₂₁)of the annular chamber (N₂₁ or N₂₁) that is concerned.

The length of a so-called annular level 1 chamber or N₁ is, for example,equal to half of the perimeter of the corresponding plate.

The length of a so-called annular level 2 chamber or N₂ is in an angularsector of 20 to 160 degrees and preferably between 100 and 120 degrees.

Zone Z₂₀, Z₂₁ can be identified by an angle α counting from a radius ofthe plate, for example the radius that passes through junction point Jand relative to the central point of the zone. Its length Zr isdetermined by, for example, the angular sector that is defined by α+/-ε,bounded by angles αmin and αmax.

The value of angle α will be in, for example, the range (10 degrees, 80degrees) and preferably in the range (40 degrees, 70 degrees).

The angular sector value will be selected in the interval (3 degrees, 30degrees) and preferably in the interval (7 degrees, 15 degrees), whichcorresponds to length Zr for zones Z₂₀ and Z₂₁.

An effort is made to ensure as star-shaped an arrangement of hoses aspossible to obtain the smallest dispersion time possible in thedistribution or extraction of the fluids. The connecting points of thehoses are grouped, for example, virtually at the same point of the zonein the smallest possible angular sector.

The positioning of the connecting hoses, and the selection of theangular sector make it possible in particular to reduce the pure delaytime and dispersion time. This delay time can thus be reduced to 10 s.

Each hose C(N₂₀)j, C(N₂₁)j for distribution and/or extraction has adiameter dj, a length lj and a connecting point rj with a level 2chamber that is located, for example, in corresponding zone Z₂₀, Z₂₁.

Different parameters, α, ε and li, are selected so that the fluidsarrive at approximately the same time in all of the panels that form aplate or during extraction of fluids reach hoses 1, 2 at approximatelythe same time.

Diameter dj of a hose is determined based on the flow rate of the fluidthat circulates to ensure a fluid circulation rate that is approximatelyidentical in the various hoses.

A connecting hose can be connected with one or more DME panels. In thiscase, it is extended by branches up to a rail for distributing orcollecting the panel.

FIGS. 2A and 2B show a plate that comprises several DME, whereby theplate is divided into four sectors according to a cutaway in parallels(of meridian type). The number of panels in this case will preferably bean even number.

FIG. 2A shows an example where the distributing-collecting system thatensures the injection of a fluid in lower rail 44 (FIG. 4) is used,whereas FIG. 2B shows the distributing-collecting system that ensuresthe draw-off from upper rail 43 (FIG. 4) in the case of a DME that hasone of the characteristics that are given in FIG. 4 and when the fluidsare grouped by function. This example is detailed in the paragraph "caseof fluids that are grouped by function" that is described below.

According to this particular embodiment, connecting hoses C(N₂₁)j orC(N₂₀)j make it possible to link an annular chamber N₂₁, N₂₀ with apanel or DME.

The example that is given above mentions an annular form for thedistributing-collecting system chambers. Without exceeding the scope ofthe invention, it is possible to design chambers N₁, N₂₀, and N₂₁ thathave other shapes that are adapted to the shape of the separation columnon which the system is arranged.

To better understand the distributing-collecting system according to theinvention, and the advantages that it provides, FIG. 3 shows a diagramof a separation column that is equipped with such adistributing-collecting system as an illustrative and nonlimitingexample.

The column is, for example, a column for separation by chromatography ina simulated moving bed. The fluids that are referred to as "secondaryfluids" can be the feedstock, the extract or the raffinate that areobtained by separation or else the desorbent that is used for extractingfrom adsorbent beds the components that have been adsorbed during theseparation process.

The column comprises a chamber 30 that is, for example, essentiallycylindrical and that includes all of the elements that make it possibleto carry out a separation by adsorption. It is also possible to useseveral columns that are connected to one another.

It is filled with an adsorbent material that has a selectivity that isselected relative to the feedstock that is treated. The adsorbentmaterial is distributed to the inside of the column in several adsorbentbeds A₁ to A_(n) of adsorbent. Two successive beds are separated, forexample, by a fluid distributor plate Pn. Each distributor platecomprises several panels or DME and is connected to a fluid distributionsystem as described in FIGS. 1 and 2.

The main fluid is drawn off from the lower end of the column via a line31 to be recycled via a pump 32 and a line 33 at the upper end of thiscolumn where it is introduced into upper adsorbent bed A₁ via lines 34.

In this embodiment, the column also comprises a bypass line Li,j betweenthe plates, whose operating principle is given in Patent Application FR97/16,273, whose teaching is incorporated with reference. Such a processmakes it possible in particular to increase the purity of the productsthat are obtained by such a process.

For the separation of paraxylene from a xylene feedstock, for example,two columns of twelve beds each are used, whereby the twenty-four bedsare divided into at least four zones, whereby each zone is delimited byan injection of a fluid from the outside of the column (of the desorbentor the feedstock, for example) and a draw-off of another fluid (extractor raffinate, for example). For example, five beds are reserved for zone1, nine beds for zone II, seven beds for zone III and finally three bedsfor zone IV.

The panels of a plate Pn are linked with, for example, the outside ofthe column via secondary fluid transfer lines (feedstock injection line36, desorbent injection line 37, draw-off line 38 of an extract anddraw-off line 39 of a raffinate, and optionally an injection line of afifth back flush fluid). The back flush lines are not shown in thefigure for reasons of simplification.

Each of these lines is equipped with a sequential valve that is shownsymbolically by Vfi, Vei, Vsi and Vri, where index i corresponds toplate Pi and where f refers to the feedstock, e the extract, s thedesorbent and r the raffinate. The set of these valves is connected tomeans for sequential swapping-out that are suited for periodicallyadvancing each injection point of secondary fluid or draw-off ofsecondary fluid from a bed in the direction of circulation of the mainfluid, i.e., from top to bottom to obtain an operation in a simulatedmoving bed.

The circuit that makes it possible to carry out the by-pass and toobtain a composition of a fluid that is essentially identical at allpoints of a plate comprises a bypass line Li,j that connects twointroduction or draw-off hoses, and two plates. According to the priorart, a bypass line comprises at least one of the devices that arementioned below, by itself or in combination, namely a nonreturn valve40, a flowmeter 41, a control valve VOi,j that may or may not be slavedto the flowmeter. A pump that is optionally arranged on the bypass lineoptionally does not ensure an adequate pressure drop.

The valve that equips the bypass or bypass line is referenced VOi,jwhere index 0 corresponds to the bypass function and indices i, jcorrespond to the plates between which the bypass is carried out.

More generally, a simulated moving bed comprises at least fourchromatographic zones, advantageously four or five, whereby each ofthese zones consists of at least one column or column section. The setof these columns or column sections forms a closed loop, whereby therecycling pump between two sections is regulated in flow rate.

These different lines can be connected with a distributing-collectingsystem provided above.

Without exceeding the scope of the invention, any network fordistribution or extraction of secondary fluids that are commonly usedfor the separation columns by adsorption can be used.

The chamber can comprise a central beam 35 that is aligned essentiallyalong the vertical axis of the chamber, more particularly for columns oflarge diameter.

In some application cases, for example for vapor phase fluids, thechamber can be arranged approximately horizontally.

A distribution plate Pn can be cut into several panels or DME accordingto a cutaway in parallels (of meridian type). Each of the panelscomprises characteristics such as those that are described below.

Plate Pn that is shown in a diagram in FIGS. 2A and 2B is divided intofour sectors, for example according to a cutaway in parallels (ofmeridian type) and comprises several DME panels, preferably an evennumber per sector.

The cutaway of panels in parallel with an approximately equal widthensures a surface density with essentially constant drainage for thepanels.

FIG. 4 presents in detail an embodiment of a panel or DME that forms theplate.

An elementary panel or DME is divided, for example, into twoapproximately equal surfaces by a distributing-collecting circuit thatis formed by the superposition of two rectangular-section boxes orrails.

A panel comprises an upper grid 40 and a lower grid 41 by taking intoconsideration the direction of circulation of the main fluid inside theseparation column. Upper grid 40 makes it possible to collect the mainfluid, whereas lower grid 41 makes it possible to redistribute themixture that is obtained from the mixing chamber over the entire panel.

Between these two grids, for example of slot type, are arranged variouselements:

two deflectors 42a, 42b, or baffles whose function in particular is toseparate the collecting channel and the distributing channel that aredescribed below,

two rails 43, 44 that allow the passage of secondary fluids; these railsare arranged one above the other, for example. Upper rail 43 can belocated above the deflectors, whereas lower circuit 44 can be positionedbetween two deflectors 42a, 42b, and its height can be such that itextends below the deflectors.

These circuits or rails 43 and 44 are provided on at least one of theirwalls with one or more orifices that are referenced respectively 43i and44i to allow the passage of the secondary fluids. In FIG. 4, orifices43i are arranged on the lower wall of rail 43, and orifices 44i arearranged on the lateral walls of rail 44; orifices 44 are arranged sothat the flows of fluids that are injected strike the end of deflectors42a, 42b, for example.

Each rail is perforated symmetrically respectively on its lower face orits lateral face for the upper rail and on these lateral faces for thelower rail. Specifications on distribution and the size of the orificesare explained below:

in the extension of deflectors 42a and 42b are arranged perforatedplates, respectively 45a, 45b (openings or slots 45ai, 45bi). Theseplates extend up to the walls of rail 44, for example. Openings 45ai,45b for output of the mixture to redistribution space 49 are, forexample, calibrated to promote transverse mixing,

a space 46 for collecting the main fluid that is delimited by upper grid40 (for reasons of mechanical design, the variant that is represented inthe figure shows a three-part grid, whereby the parts are connected toone another by walls 47a, 47b), the top of rail 43, a lateral wall ofrail 43, deflectors 42a and 42b; this space makes it possible to drainthe main fluid to the mixing chambers,

two mixing chambers 48a, 48b are arranged on both sides of lower rail(44).

Preferably, the chambers are arranged, for example, relative to orifices6i, 7i of rail 6 or 7 or both, whose function will be to inject one ormore fluids into the mixing chambers. They will be arranged to ensurethe most homogenous, uniform or symmetrical fluid injection that ispossible in the entire mixing chamber, for example.

Mixing chamber 48a is delimited by, for example, a portion of the wallof rail 43, a lateral wall of rail 44, deflector 42a and perforatedplate 45a. Mixing chamber 48b is delimited in the same way by a lateralwall of rail 44, a portion of the lower wall of rail 43, deflector 42band perforated plate 45b.

The main fluid that is collected by grid 40 travels from the collectingspace to mixing chamber 48a, 48b respectively in the form of a thinspace via the slot that is formed between the upper rail and one of thedeflectors:

A space 49 for distributing the mixture or collecting the fluid that isto be drawn off, whereby this space is delimited by lower grid 41, thelower wall of lower rail 44, when the latter is not arranged at the samelevel as grid 41 and mixing chambers 48a, 48b as well as two deflectors42a, 42b.

Because of the arrangement of the orifices, mixing chambers anddistributing and/or collecting rails, the mixture that is obtained inthe redistribution space has a composition whose homogeneity is improvedrelative to the devices of the prior art.

The rails or circuits that are intended for passage of secondary fluids,as well as the two mixing chambers, have, for example, elongatedrectangular shapes.

According to a variant embodiment, it is possible to arrange between thelower end of walls 47a, 47b and corresponding deflector 42a, 42b meansthat make it possible to create a series of calibrated orifices or slotsto inject the main fluid in the form of several jets into the mixingchambers.

The distribution of different orifices 43i, 44i at rails 43, 44 and themixing chamber is selected so that in the injection function, the fluidsthat are injected strike at least a portion of a solid wall of one ofthe elements of the DME.

For example, when rail 43 has a draw-off function and rail 44 has aninjection function, the geometric and dimensional data for orifices 43i,44i relative to the distribution rails as well as their distribution onthe various walls will be selected from among, for example, thefollowing values:

a diameter of between 2 and 15 mm and preferably in the range of 4 to 7mm,

a perforation span of between 25 and 400 mm and preferably between 50and 200 mm,

a rate of flow of the fluids of between 3-20 m/s and preferably between5-15 m/s, whereby the rate makes it possible to feed all of the orificesin the most homogenous way possible; the value of the span that is beingconsidered with the value of the rate makes it possible to obtain a goodmixing of the secondary fluid and the main fluid.

The criteria that are given for the selection of values of the rate offlow and the perforation span are valid regardless of the shape of theorifices.

As an additional characteristic, orifices 44i have an axis that makes itpossible for injected fluid to strike a portion of a solid wall of oneof the mechanical elements of the DME.

The configuration and the criteria for sizing of the draw-off networkare approximately identical to those of the injection network. Adifference exists in the perforation plane of the draw-off rail. Thediameter of the draw-off holes will be selected to obtain a span that istwice that of the injection rail and an alternate arrangement, forexample at random.

Outlet openings 45ai, 45bi of a mixing chamber or orifices for passageof the mixture will have the following characteristics:

a diameter of between 5 and 50 mm, and preferably between 10 and 25 mm,

a perforation span that is selected from the interval 25-400 mm andpreferably in the interval 50-200 mm,

a rate of flow of the mixture of between 0.5 and 3.5 m/s and preferablybetween 1.0-2.0 m/s.

Because of the arrangement of the rails, connecting hoses C(N₂₀)j areconnected to injection rails 44 by a single hose 50, and connectinghoses C(N₂₁)j are divided at extraction rail 43 (FIG. 5A) into two hoses51₁, 51₂ that are joined in a hose 51, for example.

Hoses 51₁, 51₂ are located on both sides of hose 50. These hoses arearranged to have an injection or extraction function that is the mostsymmetrical possible for rails 43, 44.

Based on the groupings of fluids, rails 43 and 44 can ensure differentfunctions: a distribution function, an extraction function or else twofunctions.

According to a variant embodiment, a DME or a panel can also be dividedinto several injecting-collecting systems therefore to comprise severalsuperposed rail systems. In this case, hoses 50, 51 are divided to bearranged relative to the upper and lower rails in a manner that isessentially identical to the one that is described in FIGS. 5A and 5B.

Case of grouping fluids by function:

Injection (FIGS. 1 and 2A)

Four hoses C(N₂₀)j with j varying from 1 to 4 make possible theinjection of fluid to four DME of a quarter plate sector,

the feedstock and/or the desorbent are introduced via hose 1 intoannular chamber N₁. The injected flow is divided into two flows thattravel through paths 11 and 12 and that correspond approximately to onehalf of the semi-circumference of the plate. Each flow then travels intoannular chamber N₂₀, in which it is divided into two flows F'1 and F"1.Each flow is then distributed from connecting hoses C(N₂₀)j that aregrouped in zone Z₂₀ and hose 50 in connection with these connectinghoses at lower rail 44 of each of the DME.

The flows that are obtained from orifices 44i will strike the end ofdeflectors 42a, 42b and are mixed with the main fluid space.

Extraction (FIGS. 1 and 2B)

Four hoses C(N₂₁)j will make it possible to extract a fluid from 4panels or DME,

the extract and the raffinate are drawn off from a rail of a panel, forexample upper rail 43, and two dipping hoses 51₁, 51₂ to hose 51. Theythen pass through connecting hoses C(N₂₁)j in connection with zone Z₂₁of a chamber N₂₁. The two flows of fluids that are collected in thezones that are positioned at the two ends of annular chamber N₂₁ aregrouped before passing into annular chamber N₁ in connection with hose 2that recovers all of the flows that are obtained from the four sectorsof the plate.

Case of grouping fluids by nature:

The fluids that are being considered as characteristic fluids are thedesorbent and the extract and the so-called "dirty" fluids, theraffinate and the feedstock.

In this case, rails 43 and 44 ensure the two distribution and extractionfunctions.

Case of grouping by flow rate:

The fluids that have, for example, a low flow rate will be the feedstockand the extract, and the fluids that have a high flow rate will be thedesorbent and the raffinate.

In this case, rails 43 and 44 ensure the two distribution and extractionfunctions.

In the two latter grouping examples, the fluids that are injected viaopenings 43i and 44i will strike a portion of the solid wallsrespectively of wall 45 and deflectors 42A, 42B. They pass through thedistributing-collecting system in connection with the panel; whereas thefluids that are to be extracted are collected in rails 43 or 44 beforebeing sent via connecting hoses to the annular chambers that arementioned above.

The orifices or passage of fluids can have any type of geometry, such asa single slot, several slots or else holes.

The injection and extraction paths are identical to those that have beendescribed in the grouping diagram by function.

The space for collecting the main fluid preferably has a shape that issuited for minimizing the dead volumes and the turbulence of the fluids.It has a height of, for example, between 3 and 25 mm and preferablybetween 7 and 15 mm, and an approximately rectangular or conical shape.It may have the characteristics that are mentioned in above-mentionedU.S. Pat. No. 5,755,960 of the applicant.

The distribution space of the mixture before the grid will bedetermined, for example, by taking into consideration the physicalcharacteristics of the main fluid.

The volume of the mixing chamber preferably will be adapted forminimizing the dead volumes. Its dimensions can be selected from amongthose that are given in one of U.S. Pat. No. 5,792,346 and U.S. Pat. No.5,755,960.

Any means for promoting turbulence can be added to the inside of themixing chamber. These means can be presented in the form of obstacles,baffles or any other means that are intended to increase theeffectiveness of the mixture. The volume of this chamber will beselected in a small enough size to minimize the influence of retromixingphenomena.

The given parameters for a DME and for the distributing-collectingsystem above by way of example in relation with a separation column ofan approximately cylindrical shape can be applied, without exceeding thescope of the invention, to a separation column that has any shapewhatsoever, whereby the distributing-collecting system then has a shapethat is suited to that of the column.

Likewise, a plate can be divided into several DEM according to a cutawayother than the cutaway in parallels, for example into sectors of piechart type.

Without exceeding the scope of the invention, the DME and thedistributing-collecting system that are described above can easily beused in separation devices that may or may not comprise a centralholding beam and that have a diameter that varies, for example, from 3to 10 m.

They can also be used for separation columns that have a diameter thatis less than or equal to 5 m and that do not comprise a central supportbeam.

In the preceding description, the terms "rail" and "circuit" are usedinterchangeably. Other possible synonyms go are "channel" and "trough".

The preceding examples can be repeated with similar success bysubstituting the generically or specifically described reactants and/oroperating conditions of this invention for those used in the precedingexamples. Also, the preceding specific embodiments are to be construedas merely illustrative, and not limitative of the remainder of thedisclosure in any way whatsoever.

The entire disclosure of all applications, patents and publications,cited above and below, and of corresponding French application98/10.998, are hereby incorporated by reference.

From the foregoing description, one skilled in the art can easilyascertain the essential characteristics of this invention, and withoutdeparting from the spirit and scope thereof, can make various changesand modifications of the invention to adapt it to various usages andconditions.

What is claimed is:
 1. Fluid distributing-collecting system for a devicefor bringing fluids and solids into contact, whereby said devicecomprises a chamber (30), at least one hose (33) for introducing a mainfluid and at least one hose (31) for evacuating the main fluid, severaldistributor plates (Pn), whereby each of said plates comprises severalpanels for mixing, distributing or extracting fluids or DME,characterized in that it comprises:at least one hose (1, 2) that makesit possible to link said device and the outside, at least one chamber(N₁) that is connected with said hose or hoses (1, 2), one or moreconnecting hoses C(N₂₀)j, C(N₂₁)j, that link the chamber and at leastone of the DME of a plate (Pn), whereby connecting points rj of saidhoses are located in a zone (Z₂₀, Z₂₁), whereby the positioning of saidzone is determined by an angle α counting from one of the radial axes ofsaid plate (Pn), whereby each of the connecting hoses has a length li,whereby the value of each of lengths li, of angle α and of length Zr ofthe zone is selected so that the passage time of the fluids between apanel (DME) and hose or hoses (1, 2) is essentially identical for all ofthe fluids.
 2. System according to claim 1, wherein said chamber ensuresthe division of the fluid into at least two flows.
 3. Fluiddistributing-collecting system according to claim 1, wherein itcomprises:at least one level 1 chamber (N₁) that ensures a twowaydivision or collection of the fluid flow, whereby said chamber (N₁) isconnected with hose or hoses (1, 2), at least one so-called level 2chamber (N₂₀, N₂₁), whereby said chambers ensure a two-way division orcollection of the fluid flow that comes from or is sent to chamber orchambers (N₁)I one or more connecting hoses (C(N₂₀)_(j), C(N₂₁)j thatextend between at least one level 2 chamber (N₂₀, N₂₁) and at least oneof the DME of a plate (Pn), whereby connecting points rj of said hosesare located in a zone (Z₂₀, Z₂₁), whereby the positioning of said zoneis determined by an angle α counting from one of the radial axes of saidplate (Pn), whereby each of the connecting hoses has a length li, andwhereby the value of each of lengths li, angle α and length Zr of thezone are selected so that the passage time of the fluids between a panel(DME) and hose or hoses (1, 2) is essentially identical for all of thefluids.
 4. Distributing-collecting system according to claim 1, whereinangle α is between 30 and 90 degrees, and length Zr for a zone thatcorresponds to angle sector α+/-ε is between 3 and 30 degrees.
 5. Thedistributing-collecting system according to claim 4, wherein the lengthZr for a zone that corresponds to angle α+/-e is between 7 and 15degrees.
 6. Device for bringing fluids and solids into contact thatcomprises a chamber (30) that comprises an outside wall, at least onehose (33) for introducing a main fluid and at least one hose (31) forextracting a main fluid, several hoses for introducing or extractingsecondary fluids, several spaced levels of plates (Pn), whereby eachplate (Pn) comprises one or more distributor-mixer-extractor (DME)panels of secondary fluids and the main fluid, at least onedistributing-collecting system of said fluids, wherein:saiddistributing-collecting system is arranged on the periphery of saidchamber, said distributing-collecting system is connected with at leastone distribution plate (Pn), said system comprises: at least one hose(1, 2) that makes it possible to link the device and the outside, one ormore level 1 chambers (N₁) that ensure a two-way division or collectionof the fluid flow, one or more level 2 chambers (N₂₀, N₂₁), whereby saidlevel 2 chambers ensure a two-way division or collection of the fluidflow that comes from or is sent to level 1 chamber (N₁), one or moreconnecting hoses (C(N₂₀)_(j), C(N₂₁)j) that extend between a level 2chamber (N₂₀, N₂₁) and at least one of the panels (DME) of a plate (Pn),whereby the connecting points of said connecting hoses are located in azone (Z₂₀, Z₂₁), whereby the positioning of this zone is determined byan angle α counting from one of the radial axes of a plate (Pn), wherebyeach of the fluid connecting hoses has a length li, the value of each oflengths li, angle α and length Zr of the zone are selected so that thepassage time of the fluids between a panel (DME) of a plate (Pn) andhose (1, 2) for introducing or extracting fluids is essentiallyidentical for all of the fluids.
 7. Device according to claim 6, whereinangle α is between 30 and 90 degrees, and wherein length Zr thatcorresponds to the angle sector is between 3 and 30 degrees.
 8. Thedevice according to claim 7, wherein the angle sector is between 7 and15 degrees.
 9. Device according to claim 6, wherein each plate (Pn) isdivided into several panels or DME.
 10. Device according to claim 9,wherein a plate is divided into four sections.
 11. Device for bringingit into contact according to claim 6, wherein it comprises at least oneplate that comprises at least one DME that has the followingcharacteristics:at least one means for collecting a main fluid (40), atleast two rails (43, 44) that allow the passage of secondary fluids thatare each provided with openings (43i, 44i), whereby said rails arearranged one on top of the other, at least two mixing chambers (48a,48b) that are provided with openings (45ai, 45bi), whereby said chambersare arranged on both sides of at least one of said rails (43, 44) andrelative to openings (43i, 44i) to obtain a homogeneous distribution orcollection of the fluid, means for distributing (41, 49) the fluid thatis obtained from the mixing chamber, means for separating saidcollecting and distributing means (42a, 42b).
 12. Device according toclaim 7, wherein said upper rail (43) has a fluid collecting function,and said lower rail (44) has a fluid injecting function.
 13. Deviceaccording to claim 6, wherein said upper rail (43) is adapted to have afluid injecting function, and said lower rail (44) is adapted to have afluid collecting function.
 14. Device according to claim 6, wherein saidupper rail (43) and lower rail (44) are adapted to have a fluidinjecting-collecting function.
 15. Device according to claim 6, whereinthe openings of rail or rails (43i, 44i) that are adapted to have aninjecting function are arranged such that the fluid jet that passesthrough strikes a portion of a solid wall of one of the mechanicalelements of the DME (42a, 42b, 45a, 45b).
 16. Device according to claim6, wherein openings (43i, 44i) are arranged alternately or at random.17. Device according to claim 6, wherein the parameter of the rails andopenings (43i, 44i) is defined by:a diameter of between 2 and 15 mm, aperforation span of between 25 and 400 mm, a rate of flow of the fluidsof between 3-20 m/s, whereby the value of the span that is beingconsidered with the value of the rate makes it possible to obtain a goodmixing of the secondary fluid and the main fluid.
 18. The deviceaccording to claim 17, wherein rate of flow of the fluids is between 5and 15 m/s;wherein the perforation span interval is between 50 and 200mm; and wherein the rate of flow of the fluids is between 5-15 m/s. 19.Device according to claim 5, wherein openings (45ai, 45bi) of mixingchambers (48a, 48b) are selected from among the following parameters:adiameter of between 10 and 25 mm, a perforation span that is selectedfrom the interval 50-200, a rate of flow of the mixture of between 1.0and 2.0 m/s.
 20. The device according to claim 19, wherein the diameteris between 5 and 50 mm;the perforation span interval is between 25-400mm; and wherein the rate of flow of the fluids is between 0.5-3.5 ms.